Manufacture of alkaline alginates.



UNITED STATES PATENT OFFICE.

THOMAS INGI-IAM, OF LIVERPOOL, ENGLAND.

MANUFACTURE OF ALKALINE ALGINATES.

SPECIFICAT N forming part of Letters Patent No. 695,209, dated March 1 0Application filed August 20, 1901- Serial No. 72,702. (No specimens.)

To all whom it may concern.-

Be it known that I, THOMAS ING-HAM, manufacturing chemist, a subject ofthe King of Great Britain, residing in Liverpool, in the cou nty ofLancaster, England, (whose full postal address is 61 Lord street,Liverpool,) have invented certain new and useful Improvements in theManufacture of Alkaline Alginates, (for which application has been madein England, under No. 22,590, and dated December 11, 1900,) of which thefollowing is a specification.

This invention has forits object an improvement in the process of makingalgin or alkaline alginate, for which the late E. 0. Stanford obtainedBritish Patent No. 142 of 1881.

In the manufacture of alkaline alginate or algin therefrom it isnecessary to form a solution of alkaline alginate containing a verylarge excess of alkali. From this an impure neutralalkalinealginateoralginic acid mixed with other salt has been obtainedby neutralizing'the excess of alkali with acetic acid or mineral acid.

Now my invention consists in taking this strongly-alkaline solution ofalginate of soda and precipitating therefrom alginic acid bysufficiently strong acid to take up all the alkali. This alginic acid oralgin is then, as

is well known, easily separated as a precipitate from the solution. Ithen take a second portion of the strongly-alkaline solution of alginateof soda and add thereto sufficient alginic acid thus precipitated tomake the Whole a pure solution of alkaline alginate. This solution cannow be evaporated down and dried.

Having thus described my invention, the following is What I claim as newtherein and desire to secure by Letters Patent:

1. The process of obtaining a pure solution of alkaline alginate whichconsists in taking the strongly-alkaline solution of alkaline alginateand neutralizing the same by alginic acid.

2. The process of making pure alkaline a1- ginate, which consists inadding to the mixture of alkaline alginate and alkali, alginic acid inthe proportions requisite to form pure alkaline alginate and evaporatingto dryness.

In witness whereof I have hereunto signed my name,this 10th day ofAugust, 1901, in the presence of two subscribing witnesses.

THOMAS INGI'IAM.

Witnesses:

WM. P. THOMPSON, SIDNEY W. D01).

